dragonfly door knocker
The metal is actually an alloy (two or more metals mixed together); usually containing 85-99% tin and the rest copper. Lower-grade pewter has a bluish color because lead is also added. Although there is little practical use for the metal today its still a popular material for decorative objects because it is easy to produce while retaining an elegant texture.Copper is renowned for its ability to withstand the natural elements; it is the only material that doesnt rust. Instead it oxidizes - which means it forms a unique green cover when exposed to oxygen (think of the statue of liberty). Besides aging gracefully copper doesnt physically deteriorate unlike other metals. The oxidation layer makes the metal stronger which reduces the need to replace any door knockers made out of copper.
The finish should match the rest of the hardware. Door knockers not only come in many finishes they are available in many types of metal. The most stable metal and probably the most common is brass. Brass is easy to machine and cast into shapes. It polishes into a bright gold like finish or satins easily and is easy to maintain. Brass also electroplates readily. This allows it to be nickel or copper plated to simulate pewter and bronze finishes. Because brass is non ferrous it will not rust. It will tarnish though for this reason a good lacquer finish is needed or your purchase will look terrible in a very short time.
In many instances the hardest part of replacing a door knocker is finding a suitable replacement. Matching the finish or style is not so difficult as is matching the mounting methods. There are two common methods of installing a door knocker. Surface mounting and through the door mounting. Both methods use common household tools. Other than that they are distinctly different. First is the surface mount method. This option uses wood screws that pass through the door knocker and into the door. This is the easiest method for replacement. The screws do not have to line up perfectly with the existing holes in the door.
There really is no limit in this genre because the knocker is meant to reflect the homeowners unique personality. Installation FAQ If you are installing a new door knocker the best choice is a rear mounted knocker made from solid materials such as brass or iron. These will be more resistant to damage over time and offer a wider option of intricate designs. Rear mounting does require the door to be drilled for installation but this prevents theft of the knocker and ensures it will not fall off or break away from the door. If you are replacing an existing knocker it is important to measure the pre-existing holes and choose a new knocker carefully.